3. Topical technique
Mode of action
Blocking nerve conduction near their site of administration, thereby
producing temporary loss of sensation in a limited area.
Absorption
Most anesthetic agents exist as solids and are only superficially
absorbed through intact skin.
Indications
I. Skin and mucous membrane conditions
II. children to minimize discomfort prior to injections or to starting an
intravenous line
4. Skin and mucous membrane conditions
• pruritus and pain due to minor burns
• skin eruptions (eg, varicella, sunburn, poison ivy, insect bites)
• local analgesia on intact skin.
5. Dosage Guidelines
and Administrative Techniques
• Apply the cream, ointment, or solution to the chosen area in
incremental amounts.
• The total dose for a topical anesthetic is smaller than that used for
subcutaneous infiltration.
• EMLA cream does not require an occlusive dressing (eg, DuoDERM,
Tegaderm, Saran Wrap); however, when an occlusive dressing is
applied, absorption is improved and time of onset is decreased.
• Viscous lidocaine may be used alone or in a compounded mixture as a
mouthwash (ie, swish and expectorate).
6. Ctd..
• Iontophoresis has been used to improve the effects of topical
anesthesia; however, the equipment is expensive and bulky, and
some patients experience discomfort from the mild electrical
sensation.
• Sequential layered application of topical lidocaine with epinephrine
(TLE) has been described for small facial or scalp wounds.
7. Adverse effects
• Burning or tingling at the sight
• CNS: Respiratory depression and seizures.
• CVS: bradycardia, arrhythmias, hypotension, cardiovascular collapse, and
cardiac arrest.
• OTHERS:
Transient burning sensation
Skin discoloration
Swelling
Neuritis
Tissue necrosis and sloughing
9. Indications
• Closed fractures
• Burn debridement
• Removal of ground in debris
• Abcess I and D
• Laceration repair
• Foreign body removal
10. Meachanism of action
Factors responsible
• A large volume of dilute anesthetic
• Ischemia
• Asphyxia
• Hypothermia
• Acidosis
11. Sequence events resulting in Anaesthesia and
Analgesia
1. Injection of local anesthetic –Analgesis
2. Asphyxia that occurs 20-30 min
3. Hypothermal acidosis
12. equipment
• 22gauge IV catheter
• Flexible extension tubing
• 5” Esmarch bandage
• Double cuff tourniquet
• 20ml syringes with local anaesthetic
• Pressure source
13. Procedure
1) A small IV catheterb is introduced in the dorsum of patients hand
2) Tourniquet is placed on the proximal arm to extremity to be blocked
3) Palpate radial and ulnar arteries to establish baseline
4) Esmarch bandage to complete exsanguination of extremity
14. 5)Elevate arm to promote venous drainage
6)Extremity lowered and local anaesthetic injected through IV catheter
Post procedure
Analgesia will occur within 3-4 minutes
At end of procudure tourniquet deflated and normal sensation quickly
returns
15. Advantages of the Bier block
• Easy to administer
• Low incidence of block failure
• Rapid onset and recovery
• Patient is awake during procudure
• Controllable extent of anesthesia
16. disadvantages
• Only for short procudures
• Patients may experience tourniquet pain after 20-30 min]
• Sudden CVS collapse if local anesthetic is released into the circulation
too early
• Lose of pulse
17. contraindications
• Reynaud disease
• Homozygous sickle cell disease
• Young chidren
• Multiple tauma
• Seizure disorder
• Hypersensitivity to prilocaine or lidocaine
18. Drugs
• Prilocaine
Drug of choice-least toxic with large therapeutic index
Onset 2-15 minute and duration 1-4 hours
• Lignocaine
accepteble alternative onset 1.5-5 minute and duration 1-4 hours
Dosage 30-40ml of 0.5% prilocaine or 0.5% lidocaine
In leg 50-60ml
19. Complications
• Tourniquet pain
• At IV site blotchy erythema urticaria and flushing
• Tourniquetb fails
Headache ,lethaergy slurred speech seizure hypotension bradycardia
20. PERIPHERAL NERVE BLOCK
Also known as local anesthetic nerve blockade
It’s a short-term nerve block involving the injection of local anesthetic as close as possible to
the nerve for pain relief
This will then numb the area of the body supplied by that nerve.
AIM: to prevent pain by blocking the transmission of pain signals from the surgical site.
21. Mechanism of action
• Local anesthetics act on the voltage gated sodium channels that
conduct electrical impulses and mediated fast depolarization along
nerves. Most of the local anesthetics target open channels and
prevent ion flow.
• They also act on potassium channels but they block sodium channels
more.
22. Common local anesthetics
• Local anesthetics are broken down into 2 categories:
1. Amide-linked: Lidocaine, bupivacaine, ropivacaine,
mepivacaine,(these are commonly used) prilocaine
2. Ester-linked: (rarely used for peripheral nerve block) benzocaine,
procaine, tetracaine, chloroprocaine
23. • These drugs are commonly used with adjuvants to increase the duration of
anesthesia or to shorten time of onset.
• They include: epinephrine, clonidine, and dexmedetomidine
• Vasoconstriction caused by local anesthetics maybe further enhanced
synergistically with the addition of epinephrine. It decreases blood flow by
acting as an agonist at the alpha1 receptor
24. Duration of nerve block
• These depends on the type of anesthetic and used and the amount
injected around the target nerve.
• Short-acting: (45-95 min)
• Intermediate-acting (90-180 min) ie; lidocaine, mepivacaine,
• Long-acting (4-18hrs): bupivacaine, ropivacaine
25. • Local anesthetic nerve blocks are sterile procedures that can be
performed with the help of anatomical landmarks, ultrasound,
fluoroscopy (a live X-ray), or CT. these enables the physician to view
the placement of the needle
• Electrical stimulation can also provide feedback on the proximity of
the needle to the target nerve.
26. Locations of peripheral nerve block
• Upper extremity:
1. Interscalene brachial plexus block: done before shoulder, arm, and elbow
surgery.
2. Supraclavicular and infraclavicular blocks: performed for surgeries on the
humerus, elbow, and hand
A pneumothorax is a risk with this blocks so the pleura should be checked
with u/s to make sure the lung wasn’t punctured during the block.
Axillary block: for elbow, forearm, and hand surgery. It anesthetizes the
ulnar, median and radial nerves
27. Lower extremity:
• Femoral nerve block: for femur , anterior thigh, and knee surgery.
The nerve is under the fascia iliaca
• Sciatic nerve block: done for surgeries at or below the knee. Nerve is
under glut maximus
• Popliteal nerve block: for ankle, achilles tendon and foot surgery
• Saphenous nerve block: done in combination with popliteal block for
surgeries below the knee.
28. • Paravertebral nerve block: is versatile and can be used for various
surgeries depending on the vertebral level it is done.
• Provides unilateral analgesia but bilateral blocks can be done for
abdominal surgery.
• Since its unilateral it can be chosen over epidurals for patients who
can’t tolerate the hypotension after bilateral sympathectomy
29. Adverse effects
For paravertebral nerve block: pneumothorax, vascular puncture,
hypotension, and pleural rupture
Toxicity of the local anesthetic can lead to: 1.tingling around the
mouth, 2. ringing in the ears, 3.metallic taste 4. seizures 5.
arrhythmias 6. cardiac arrest
Nerve injury may also occur.
Though this has been reduced by use of u/s
30. BRACHIAL PLEXUS BLOCK
• Brachial plexus block is a regional anesthesia technique that is
sometimes employed as an alternative or as an adjunct to general
anesthesia for surgery of the upper extremity. .
31. • This technique involves the injection of local anesthetic agents in
close proximity to the brachial plexus, temporarily blocking the
sensation and ability to move the upper extremity.
• The subject can remain awake during the ensuing surgical procedure,
or s/he can be sedated or even fully anesthetized if necessary
32. Anatomy
• Some mnemonics for remembering the branches:
• Posterior Cord Branches
• STAR - subscapular (upper and lower), thoracodorsal, axillary, radial
•
• Lateral Cord Branches
• LLM "Lucy Loves Me" - lateral pectoral, lateral root of the median nerve,
musculocutaneous
•
• Medial Cord Branches
• MMMUM "Most Medical Men Use Morphine" - medial pectoral, medial
cutaneous nerve of arm, medial cutaneous nerve of forearm, ulnar, medial root
of the median nerve
33. Technique for blocking nerves of brachial
plexus
• Are classified according to level of injecting local anaesthetic.
• Interscalene block nerve - block on neck
• Supraclavicular -posterior to sternocledomastoid above clavicle.
• Infraclavicular block _below clavicle
• axillary block _in the axilla
34. • Nerve stimulator is used frequently to locate nerve more precisely.
• Procedure can be used for wide range of surgical procedure below
and above elbow and provides good analgesia in the immediate
post_operative period
35. Side effects
• Temporary paresis of thoracic diaphragm in people who undergoe
interscalene or supraclavicular brachial plexus block.
• Horner's syndrome
• Difficult in swallowing.
36. Lumbar plexus block
• Lumbar plexus block carries a higher risk of local anesthetic toxicity
than most other nerve block techniques because of its deep location
and the close proximity of muscles
• The lumbar plexus block targets three main nerves supplying the
lower limb which arise from the lumbar plexus.
•
37. • This block is also called a psoas compartment block.
• The three nerves which are targeted are the femoral, obturator and
lateral femoral cutaneous nerve
• The patient is in the lateral decubitus position with a slight forward
tilt.
38. • The foot on the side to be blocked should be positioned over the
dependent leg so that twitches of the quadriceps muscle and patella
can be seen easily.
• The operator should assume a position from which these responses
are visible.
• Palpation of the anterior thigh can be useful to make sure the motor
response is indeed that of the quadriceps muscles.
39. •
• A 10 cm needle is inserted with no medial (towards spine) or lateral
angulation.
• If the transverse process is encountered then the needle is walked off
the transverse process either in cephalad or caudal direction.
• When the needle is in an ideal position then quadriceps twitches are
seen.
• Local anaesthetic is injected after a sensible threshold current (around
0.5mA) is obtained.
40. Indications
• The main indication is surgery on hip joint (e.g. hip replacement,
surgery for fracture neck of femur).
•
42. Complications
• Local anaesthetic toxicity
• Damage to retroperitoneal structures e.g. kidney,bowel etc or retroperitoneal
haematoma.
• Total spinal anaesthesia
• Death
43. NEUROAXIAL BLOCK
Definition
Neuraxial anesthesia is a type of regional anesthesia that involves
injection of anesthetic medication in the fatty tissue that surround the
nerve roots as they exit the spine (also known as an epidural) or into
the cerebrospinal fluid which surrounds the spinal cord (also known as
a spinal)
44. Anatomy of the spine
• The spine is composed of the vertebral bones and intervertebral disk.
There are 7 cervical (C), 12 thoracic (T), and 5 lumbar (L) vertebrae
• The spinal cord extends from foramen magnum to the level of L1 in
adults and L3 in children
• Each vertebra consists of a pedicle, transverse process, superior and
inferior articular processes, and a spinous process.
45.
46.
47. Types of neuroaxial blocks
Epidural anaesthesia
• Epidural (extradural) anaesthesia involves the deposition of a local anaesthetic
drug into the potential space outside the dura . This space extends from the
craniocervical junction at C1 to the sacrococcygeal membrane, and anaesthesia
can theoretically be safely instituted at any level in between.
• In practice, an epidural is sited adjacent to the nerve roots that supply the
surgical site; that is, the lumbar region is used for pelvic and lower limb surgery
and the thoracic region for abdominal surgery. A single injection of local
anaesthetic can be given, but more commonly a catheter is inserted into the
epidural space and either repeated injections or a constant infusion of a local
anaesthetic drug is used.
•
48. Spinal anaesthesia
• Spinal (intrathecal) anaesthesia results from the injection of a local
anaesthetic drug directly into the cerebrospinal fluid (CSF) within the
subarachnoid space . The spinal needle can only be inserted below the
second lumbar and above the first sacral vertebrae; the upper limit is
determined by the termination of the spinal cord and the lower limit by the
fact that the sacral vertebrae are fused and access becomes virtually
impossible. A single injection of local anaesthetic is normally used, thereby
limiting the duration of the technique.
49. Indications
Used as the primary anaesthetic technique in
• Lower abdominal
• Inguinal
• Urogenital
• Rectal
• Lower extremity surgery
50. Contraindications
• Infection at the site of infection
• Patient refusal
• Coagulopathy and bleeding disorders
• Servere hypotension
• Increased ICP
• Servere aortic stenosis
• Servere Mitra stenosis
